A cleaner available nowadays generally includes a dust barrel, a filter assembly and a motor assembly which are all located within a housing, and the motor assembly is communicated with the dust barrel through the filter assembly. The motor assembly includes a motor and a fan, and blades of the fan have a certain angle, so that the blades look like airplane propellers. The motor drives the fan blades to operate at a high speed when it is powered on, such that vacuum state is instantly formed inside the cleaner, and air pressure inside the vacuum cleaner is significantly lower than the pressure outside. Under this air pressure difference, dust and filth may enter into the dust barrel of the cleaner with the airflow through a nozzle and a air duct and then are filtered by the filter assembly, the grime may stay in the dust collection bag of the filter assembly, and the purified air is effused back to the room through the motor, by which the motor is chilled down and the air is purified.
To improve the cleaning efficiency against the ground, in addition to using the vacuum cleaning described above, a concave cavity is usually provided in the cleaner, and inside of which a roller brush is arranged. There are two objectives to arrange the roller brush, one is to increase the degree of vacuum in the dust suction port; the other is to slap against the ground so as to make the dust on the ground raised in the air, so that the raised dust is collected into the cleaner.
The detail will be shown in FIG. 1 and FIG. 2. FIG. 1 is a diagram of the local spatial structure of a conventional cleaner, and FIG. 2 is a cross-sectional view of a roller brush assembly of the conventional cleaner of FIG. 1. As shown in FIG. 1 and FIG. 2, the cleaner mainly consists of a housing 100 and a roller brush assembly 3, wherein the roller brush assembly 3 consists of a brush body 32 and multi-group tufting 311, the brush body 32 also has brush shafts 321, 321′ thereon, and a synchronous pulley 33 on which a synchronous belt (not shown) is disposed is mounted on the brush shaft 321, and the synchronous belt is driven by the motor or other drive mechanism provided in the cleaner. The roller brush assembly 3 is disposed in a concave cavity 12 of the housing 100, and two ends of the roller brush assembly 3 are mounted on the end portions of the concave cavity 12 by means of bearing 35 which is disposed over the brush shaft 321′. A bearing rubber 34 is arranged on the end portion of the bearing 35, and a wool felt 36 of the roller brush and a felting retaining ring 37 are arranged on the end portion of the brush body 32. The multi-group tufting 311 are spirally arranged on the brush body 32. By the driving of the motor or other drive mechanism provided in the cleaner, the brush body 32 rotates at a high speed, such that the tufting 311 thereon may slap against the ground, by which the dust is raised in the air and easy to be collected into the cleaner. However, since there are always some soft materials, such as hair, thread of sewing, on the ground to be cleaned, especially on the floor of some families, and these soft materials may be prone to stick on the bristles of the roller brush, then move towards the ends of the roller brush while the brush is rotating, and finally get into the gap between the roller brush and the cleaner housing. In view of this, when there are too much of these soft materials in the gap between the roller brush and the cleaner housing, on the one hand, the flexibility of the brush shaft may be affected; on the other hand, these soft materials may get around the bearing and entangle the synchronous belt, which may also affect the flexibility of the brush shaft, such that, at least, the dust collection efficiency may be lowered and the burden of the driving mechanism (such as motors) may increase; to be severe, the brush shaft may get stuck or the synchronous belt may be tangled deadly so as to damage the shaft, motor and so on.
In addition to the above mentioned in FIG. 1 and FIG. 2 that the bristle brush in the prior art may be tangled in bearing, shaft or synchronous belt, likewise, the similar problem may also happen to the leather brush in the prior art. FIG. 3 is a cross-sectional view of a leather brush assembly of the ordinary cleaner in the prior art. The leather brush assembly includes a brush body 32 and brush leather facing 31; similar to the bristle brush, both ends of the brush body 32 are respectively provided with a bearing 35, a bearing rubber 34 and brush shafts 321 and 321′, and a synchronous pulley 33 is disposed on the brush body 32 and connects with a driving mechanism (such as motor) provided in the cleaner via a synchronous belt (not shown). Because of the gap between the synchronous pulley 33 and brush body 32, most hair on the ground may tangle around the outer circular face of the roller brush and finally get the bearing, shaft stuck or the synchronous belt tangled deadly while the brush is conducting the rotation operation.
The situation described above not only happens to the cleaner, the same situation but also occurs to an independent part—the suction nozzle.
In view of the above problem, Chinese patent CN1768674A discloses a suction nozzle structure for preventing foreign object, such as hair, thread, from tangling the synchronous belt, as shown in FIG. 4 and FIG. 5, which provides a disc-shaped foreign object blocking plate 48 on one end of the roller brush that is near the synchronous belt. However, in the practical manufacturing, it is hard for foreign object blocking plate and the bottom housing of the suction nozzle to perfect match or be completely sealed with each other, there is still small space between foreign object blocking plate and the cleaner housing, foreign object, such as hair, still can tangle the synchronous belt through this space, and finally make the roller brush disabled.